Star-shaped copolymers based on the linear core poly(ethylene oxide)-poly(propylene oxide) triblock (PEO-b-PPO-b-PEO) and poly(methyl methacrylate) (PMMA) arms were synthesized via a divergent approach. The PEO based chain was firstly dendronized with a polyester system that increased the num- ber of hydroxyl groups per each terminal chain affording cores of generation 1 (G1, two hydroxyl groups per terminal chain) and 2 (G2, four hydroxyl groups per terminal chain). These were used as macroiniti- ators in the Atom Transfer Radical Polymerization (ATRP) of methyl methacrylate. The copolymers, char- acterized by different number and length of PMMA blocks, were studied by 1H-NMR, GPC, DSC. A study of influence of architecture on physical properties such as mechanical properties, water sorption and oxy- gen permeability, was also performed. It was found that both oxygen permeability and water sorption are enhanced with respect to the PMMA homopolymer by a magnitude influenced by the structure. Differently, the values of Young’s modulus remained comparable to that of PMMA.
Synthesis and Characterization of Novel Star-like PEO-PMMA Based Copolymers
GORRASI, Giuliana;IZZO, Lorella
2011-01-01
Abstract
Star-shaped copolymers based on the linear core poly(ethylene oxide)-poly(propylene oxide) triblock (PEO-b-PPO-b-PEO) and poly(methyl methacrylate) (PMMA) arms were synthesized via a divergent approach. The PEO based chain was firstly dendronized with a polyester system that increased the num- ber of hydroxyl groups per each terminal chain affording cores of generation 1 (G1, two hydroxyl groups per terminal chain) and 2 (G2, four hydroxyl groups per terminal chain). These were used as macroiniti- ators in the Atom Transfer Radical Polymerization (ATRP) of methyl methacrylate. The copolymers, char- acterized by different number and length of PMMA blocks, were studied by 1H-NMR, GPC, DSC. A study of influence of architecture on physical properties such as mechanical properties, water sorption and oxy- gen permeability, was also performed. It was found that both oxygen permeability and water sorption are enhanced with respect to the PMMA homopolymer by a magnitude influenced by the structure. Differently, the values of Young’s modulus remained comparable to that of PMMA.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
